Damage by phytophagous insect pests to geotropic propagules such as seeds, rhizomes, tubers, bulbs or corms, and plants derived therefrom causes significant economic losses.
Anthranilic diamides, alternatively called anthranilamides, are a recently discovered class of insecticides having activity against numerous insect pests of economic importance. PCT Publication WO 03/024222 discloses treatment with anthranilic diamides being useful for protecting propagules from phytophagous invertebrate pests. Furthermore, because of the ability of anthranilic diamides to translocate within plants, not only the propagules, but also new growth developing from the propagules can be protected.
Although anthranilic diamides have properties making them suitable for protecting propagules and developing growth, achieving sufficient absorption of anthranilic diamides into the propagule and developing roots to cause insecticidally effective concentrations in parts of the developing plant for which protection is desired can be problematic. Although anthranilic diamide coatings on propagules are exposed to moisture from the propagules and surrounding plant growing medium (e.g., soil), the low water solubility of anthranilic diamide insecticides impedes their mobilization through moisture. Also, until the anthranilic diamides are absorbed into the propagules and developing roots, they are vulnerable to absorption and dissipation through the growing medium.
Achieving insecticidally effective concentrations of anthranilic diamides in foliage by treating propagules requires greater amounts of anthranilic diamides to be available for transport greater distances within the plant. Because the rapidly expanding volume of plant tissue in growing foliage inherently dilutes anthranilic diamide concentrations, absorption of increased amounts of anthranilic diamides is required for protection of foliage, particularly if protection of foliage beyond the first couple leaves and during a substantial part of the growing season is desired.
Accordingly, need exists for new compositions promoting the absorption of anthranilic diamide insecticides into propagules and developing roots. Such compositions have now been discovered.